The first results of the most comprehensive genetic survey of cancer ever to be undertaken by an international consortium of researchers have just started to come in. The consortium is mapping mutations of different types of cancers with the aim of better targetting treatment.
The findings for pancreatic cancer were published in the peer-reviewed journal Nature this morning. Professor Andrew Biankin from the Kinghorn Cancer Centre at the Garvan Institute of Medical Research and I led this survey, which sequenced the genomes of 100 pancreatic tumours from Australians and North Americans and compared them to normal tissue.
Pancreatic cancer and genome mapping
Pancreatic cancer is not the most common cancer to afflict Australians. It’s actually tenth on the list, but it kills more people than melanoma. And fewer than 5% of patients diagnosed with pancreatic cancer will survive more than five years. It’s one of the few cancers for which survival rates have not increased over the past 40 years.
The problem is that it’s a complex cancer that usually isn’t detected until it has spread. Clearly, there’s a lot of scope to better understand this disease and how we can treat it more effectively.
Our project is part of the International Cancer Genome Consortium (ICGC), which has brought labs across the world together to sequence the genomes of 50 different types of tumours.
Cancer arises from the accumulation of genetic damage. You can compare it to randomly deleting files from a hard drive. Some files, if deleted, won’t make any difference to the functioning of the computer at all, while others are vital. If these files are deleted, the computer will cease functioning.
The cancer genome consortium is seeking to identify these mutations – the ones that cause a healthy cell to turn cancerous – and make this data freely available to scientists and clinicians. It’s been 12 years since the draft copy of the human genome was made public, and in that time, sequencing technology has made incredible advances.
The Human Genome Project took over a decade and cost over US$2 billion. In our laboratories at the University of Queensland’s Institute for Molecular Bioscience, we can sequence a genome in a matter of days for a few thousand dollars.
Across the 100 pancreatic cancers we studied, we identified over 2,000 mutations, a small number of which appear to be the genes that really drive the formation of tumours. We’ve also learnt that, as with many other types of cancer, pancreatic cancer is actually an umbrella term.
This means there are many sub-types of pancreatic cancer, each with different prognoses and different potential treatments. These differences can’t be seen with a microscope; sequencing is required to pinpoint what sets one tumour apart from the next.
With patients, for patients
This research, indeed that of the whole of the International Cancer Genome Consortium, wouldn’t have been possible without the cancer patients who donated their samples. They did so because they wanted to make a difference, and that’s the overarching aim for this project.
Our findings emphasise the importance of treating patients as individuals, because when it comes to cancer types and treatments, one size most definitely does not fit all.
Our research aims to take the guesswork out of chemotherapy by allowing doctors to match the genetics of a person’s tumour with a treatment. We found some patients with mutations in genes that are commonly associated with other types of cancer, such as breast cancer.
The good news for these people is that some of these genes are already treatable with drugs and, in some cases, we were able to direct their doctors to treat them with the correct drug. Next year, we’ll begin clinical trials to assess the benefit of using this method of treating patients versus standard chemotherapy in advanced pancreatic ductal adenocarcinoma.
This type of personalised medicine, where the individual is treated rather than the disease, is the future of medicine. It probably won’t be too many years before it will be standard procedure to have your diseased cells sequenced and your genetic make-up examined to determine treatment.
Of course, there’s more work to be done, but we hope our research can make a difference sooner rather than later in the lives of those affected by pancreatic cancer.
And with scientists and clinicians from around the world joining forces through the International Cancer Genome Consortium, we hope that cancer’s reign as one of our most devastating diseases will be over sooner rather than later.